Yes, cocoa is fermented– along with rice, wine, beer, coffee and some tea and other foods.
Does fermentation mean chocolate’s alcoholic? Well NO.
Does it mean chocolate has health benefits akin to cultured products like yoghurt? Probably no.
Does chocolate have other health benefits? Many are claimed; some verifiable and others a marketer’s dream but worth a subsequent blog topic.
Fermentation
Cocoa fermentation is a natural process: the outer whitish fibre of the cocoa bean dissipates and the naked coca bean remains, ready for drying and roasting.
Good cocoa flavour development depends on the fermentation process. Good quality cocoa beans which are not fermented well don’t have the flavour development necessary for producing good quality chocolate. Poorly fermented beans often develop off-flavours or have high acidity.
Ghana cocoa is widely regarded as the world’s best quality ‘bulk’ cocoa. It has a reputation for good and very consistent flavour attributed to a diverse, diligent grower base and a national quality assurance and marketing system. Ghana cocoa provides a standard against which other cocoas can be benchmarked. Conversely, much cocoa from Indonesia and Southeast Asia is of low and variable quality due to poor or non-existent fermentation practices. Some good quality Asian cocoa is produced from particular estates or regions where fermentation and drying are well managed.
Although fermentation is a complex process, the traditional techniques are simple and only basic hardware is required. The most primitive method is to wrap a ‘heap’ of cocoa beans in banana leaves. A slightly more sophisticated technique is to use specially constructed baskets or trays. The most common technique used in larger plantations, however, is to use slatted hardwood boxes which allow aeration and drainage of liquid ‘sweatings’.
In all cases, the fermenting beans are periodically ‘turned’ which aerates the mass of beans. Fermentation is generally conducted over five to seven days.
In practice things can and do go wrong; if everything goes right, however, the end result is cocoa of outstanding flavour. The challenge of course is to get everything right every time. So what can go wrong? Most issues arise with temperature which can greatly influence the fermentation success.
At Mission Beach we’re at the southern end of the latitude range for growing and processing cocoa. Our challenges are typically due to low winter temperatures. The most successful fermentations occur when the active fermentation starts almost immediately after the pods are opened and the beans extracted. The natural fermentation process is enabled when airborne and on pod wild yeasts react naturally with the fruit’s sugar component.
The fermentation cycle
At fermentation early stages, the bean mass will be at ambient temperature–this could be 20 0C in winter or 35 0C in summer. As the fermentation starts the temperature of the mass increases.
Good fermentation happens at above 45 0C. Therefore in winter we need to rise the cocoa mass by 25 0C; in summer by only 10 0C. At 45 0C temperature the ‘right’ yeasts are at work. At lower temperatures bad yeast and bacteria take over potentially contributing to ‘off’ flavours. So in winter heat pads are used to wrap the fermentation vessels or alternatively they are placed in heated spaces. Either works well.
Once the temperature is at the 45 0C point it remains there for approximately five days before declining, at which point different, undesirable yeasts and bacteria start to multiply. It’s therefore imperative to stop the fermentation at this exact point. Fermentation is stopped by putting the beans out in a thin layer no more than two beans thick for drying.
So, the bad yeasts have been tamed. The dried fermented beans are now in perfect condition for the next eight steps to produce delicious Charley’s chocolate.
Source
Yan Diczbalis, ‘Producing Cocoa in Northern Australia’, Australian Rural Industries Research and Development Corporation